A diminutive or nature-inspired nickname
In English-speaking contexts, Moo is almost exclusively used as a playful nickname or a term of endearment. It is often derived from names like Maureen or Muriel, or used as a whimsical reference to the sound a cow makes. In some Southeast Asian cultures, particularly Thai, Moo is a common nickname meaning 'pig', often given to babies to ward off evil spirits by suggesting the child is not overly precious.
A character in the animated series · Monster Rancher
A school of martial arts founded by Hwang Kee
US births per 5-year period, 1990–present (SSA data).